Launch vehicles can use pressure fed cycle in any stage of the rocket, but here i am interested for those vehicles which used this cycle in all stages. What is the current record in terms of mass of payload delivered to LEO for such vehicles? I don't count suborbital flights and vehicle must be launched from Earth. Also i don't count conceptual vehicles, only one which successfully delivered payload in LEO.
AFAIK it is "0.0 kg".
I don't know of any successful orbital vehicle with all pressure-fed stages, but maybe there's an obscure one out there.